1. Field of the Invention
The present invention relates to an image processor for irradiating an original with light emitted from a light source lamp so as to read image information formed on the original by the light reflected on the original. Based on the image information read by the image processor, a copying machine performs printing on a recording sheet to restore the image information, a scanner converts the image information into data which can be used in a computer, and the like.
2. Description of the Related Art
In the image processor of stationary original type, scanning is performed to gain image information per line while a light source lamp is moved with respect to an original placed on a platen glass. A fluorescent lamp is used as the light source lamp, and a fluorescent lamp inverter is used for supplying a voltage for driving the fluorescent lamp. In order to gain the image information by scanning the original, the light source lamp is mounted on a carriage, which can be freely moved along the original. Furthermore, the carriage provided with the light source lamp is a full-rate carriage movable by a distance substantially equal to the length of the platen glass in such a manner as to scan the original of a maximum size placed on the platen glass. Moreover, since the fluorescent lamp inverter need be moved together with the scanning of the light source lamp, it is fixed to the full-rate carriage, as disclosed in, for example, Japanese Patent Application Laid-open No. 6-308627.
FIG. 3 illustrates the schematic structure in which a fluorescent lamp inverter is provided in a full-rate carriage 1. The full-rate carriage 1 is fixed to an image processor in such a manner as to be moved in a direction indicated by a double-headed arrow P in FIG. 3; wherein one head P1 of the arrow P indicates a scanning direction and the other head P2 indicates a returning direction in which the carriage returns to its start position after the completion of the scanning. A fluorescent lamp inverter 2 is disposed forward in the scanning direction of the full-rate carriage 1, i.e., at a hatched portion A by appropriate means.
In the full-rate carriage 1, a supporter la extends in the scanning direction for securing a stable movement, as shown in FIG. 3, and is formed into a U-shape as viewed in plan. As shown in FIG. 4, since a half-rate carriage 3 movable by substantially a half of the moving distance of the full-rate carriage 1 is intruded into the U-shaped inside portion of the supporter 1a, the fluorescent lamp inverter 2 cannot be disposed in the U-shaped inside portion of the supporter 1a. The combination of the full-rate carriage 1 and the half-rate carriage 3 is directed to keep the length of an optical path constant. That is, the light reflected on the original is reflected in sequence by a first reflector, not shown, fixed to the full-rate carriage 1 and a second and a third reflector, neither shown, fixed to the half-rate carriage 3, and then, enters into photoelectric converter such as a CCD (a charge-coupled device) through a focusing lens. The length of the optical path from the original to the photoelectric converter can be kept constant also by the movements of the carriages 1 and 3.
However, as shown in FIG. 3, when the fluorescent lamp inverter 2 is fixed to the full-rate carriage 1, the hatched portion A shown in FIG. 3 possibly projects from the full-rate carriage 1 in the direction indicated by the head P1 of the arrow P. Since this direction indicated by the head P1 is the scanning direction, a portion capable of relieving the portion A need be formed in a casing of the image processor in the state in which the full-rate carriage 1 is moved up to a scanning ending position in the case where the entire original is scanned. This may put an obstacle in the way of miniaturization of an image processor. In view of this, if the fluorescent lamp inverter is fixingly disposed at an appropriate position in the image processor in such a manner as to dispense with the portion A, a harness for connecting the fluorescent lamp inverter and the light source lamp to each other is lengthened, to induce occurrence of voltage noise, with an attendant danger of instability of the light emitted from the light source lamp.
Furthermore, like an image processor disclosed in Japanese Patent Application Laid-open No. 10-51597, a fluorescent lamp inverter is attached to a conveyor belt for driving a half-rate carriage, and is conveyed at a half of a rate of a full-rate carriage, wherein the fluorescent lamp inverter and a light source lamp are connected to each other via a bendable harness unit. However, the structure for fixing the fluorescent lamp inverter to the conveyor belt may possibly become complicated, the harness may be possibly bent or stretched, and further, occurrence of voltage noise cannot be suppressed because the harness needs a certain length.
In view of this, an object of the present invention is to provide an image processor which is configured such that a fluorescent lamp inverter is fixed to a full-rate carriage mounting a light source lamp thereon in as close arrangement as possible, occurrence of voltage noise can be suppressed, and no space for accommodating the fluorescent lamp inverter need be defined even at a scanning ending position of the full-rate carriage, thereby achieving miniaturization.
As technical means for achieving the above-described object, an image processor according to the present invention for scanning an original at irradiation positions sequentially varied by moving a light source lamp with respect to the original so as to optically gain image information on the original comprises an inverter for the light source lamp disposed at an end in a direction perpendicular to a scanning direction of a carriage mounting the light source lamp thereon.
Since the inverter is disposed in the carriage mounting the light source lamp thereon, a harness or the like connecting these components to each other cannot be lengthened, thereby suppressing occurrence of voltage noise. Furthermore, since the inverter is disposed at the end of the carriage, no space for accommodating the inverter in the scanning direction need be defined at a scanning ending position of the carriage, thus achieving miniaturization of a casing for accommodating the carriage, and further, achieving miniaturization of the image processor.
Moreover, the image processor according to the invention as claimed in claim 2, for scanning an original at irradiation positions sequentially varied by moving a light source lamp with respect to the original so as to optically gain image information on the original, comprises: a carriage movable in a scanning direction, the carriage mounting the light source lamp thereon; guide means disposed in a casing along the scanning direction, the guide means mounting thereon both ends of the carriage in a direction perpendicular to the scanning direction, for supporting the carriage and guiding the movement of the carriage; and an inverter for the light source lamp disposed at the end mounted on the guide means for the carriage.
Since the inverter is supported via the carriage by the guide means for supporting the carriage, the carriage can be stably moved without any deformation.
Additionally, in the image processor according to the invention as claimed in claim 3, component parts of the inverter are disposed at the ends, respectively, in appropriate separation.
Since the component parts of the inverter are constituted of parts, which are easy, to be separated the connection or wiring between the parts cannot become complicated.
Furthermore, in the image processor according to the invention as claimed in claim 4, the component parts of the inverter are disposed at the ends, respectively, in the distribution of substantially equal weights.
If the component parts of the inverter are separated in the distribution of substantially equal weights, the weights born at the ends of the carriage become equal to each other, thereby achieving a more stable movement.